Conched chocolate

ABSTRACT

A process and a system for combining and physically working chocolate-making ingredients are provided. A variable frequency drive controls the motor of a conching device to increase the efficiency by which energy is imparted to chocolate ingredients during conching. This automatic variable speed approach permits the power to be maintained at a relatively constant and maximum rate, with the speed being determined by the consistency of the ingredients themselves. Feedback associated with the automatic speed variation can be used in order to reduce conching times and vary the quantity of certain ingredients and the timing of and location of their introduction. By the invention, it is possible to standardize the chocolate product during the conching operation and thereby avoid a post-conching standardization procedure with respect to characteristics such as viscosity and fat content.

This application is a continuation of application Ser. No. 273,709,filed Jul. 12, 1994, U.S. Pat. No. 5,460,840, which is a continuation ofapplication Ser. No. 024,268, filed Mar. 1, 1993, U.S. Pat. No.5,332,588, which is a continuation of application Ser. No. 862,972,filed Apr. 3, 1992, U.S. Pat. No. 5,200,220.

BACKGROUND AND DESCRIPTION OF THE INVENTION

The present invention generally relates to the production of chocolateby an improved process and system. More particularly, the inventionrelates to chocolate production that includes imparting a substantiallyconstant power level to the chocolate refinings being conched. Includedis an arrangement for varying the drive speed of the conching equipmentin response to the changing consistency of the intermediate chocolateproduct being conched. The invention enhances chocolate productionefficiency by making additional energy available in order to achieve oneor more advantages, especially reduction in processing times andoptimization of the addition of costly ingredients such as cocoa butter.

Chocolate is a mixture of finely milled solids, chocolate liquor, sugar,milk crumb or powder, all suspended or well dispersed in cocoa butterand/or substitute fat, which at normal processing temperature is theliquid carrying medium. Raw materials such as chocolate liquor, sugar,water and milk are processed into chocolate through a series ofprocessed steps including, for example, crumb making, paste mixing,refining, conching and standardizing. Usually, an emulsifier or anemulsifying system is added during conching.

During conching, chemical and physical processes take place. Theseinclude the development of the full desirable chocolate flavor and theconversion of the powdery, crumbly refined product into the chocolate.Conching imparts shearing stresses and kneading action which serve bothto liquify the masse and to positively influence and accelerate theflavor development processes. Important physical tasks of conching areto disperse, to dehumidify or remove moisture, to remove unwantedvolatile flavors, to break up solid particle agglomerates, to roundparticle edges and to homogenize. Viscosity is lowered, and flowabilityand texture are improved.

It is generally accepted that longer conching times produce betterchocolate. Enough time is needed to develop proper texture, goodmechanical properties, good flavor and the like. A good conchingprocedure carefully works the chocolate refinings in order to removeundesirable volatiles while releasing other flavor notes that contributeto taste and odor qualities desired of the particular chocolate beingmanufactured. Conching also effects a natural moisture reduction, atypical chocolate product having moisture levels of below one percent byweight. While longer conching times are generally preferred, commercialchocolate-making operations do place a premium on efficiency. Ideally,this efficiency should not be at the expense of desirable chocolateattributes. For example, chocolate attributes are affected by conchingpower and heat development. While it is generally beneficial to impartadequately high power levels during conching, the power imparted to thematerials being conched should be kept congruent with the consistency ofthe product itself in order to most appropriately achieve the benefitsof conching. While a temperature rise can be a characteristic of manyconching procedures, uncontrolled heat development caused by conchingfriction can result in off-flavors.

Conching procedures and equipment have evolved over the years. Earlyconches were of the longitudinal type having long marble tubs withraised sides forming a shell. In this shell, an undulating graniteroller worked and mixed the chocolate for from 24 to 36 hours. Later,classical vertical mixers such as those developed by Petzholdt were ableto reduce conching time to between about 5 to 8 hours by using plow andshear blades to tumble dry refinings in the beginning of dry conchingand then, when the mass is plasticized, put energy into the materialbeing conched. Another current rotary conch incorporates a horizontalmixer design which has three shafts with kneading and shearing bladesattached. The center blade rotates in one direction and the two outboardshafts rotate the opposite direction, which directions are reversed whendesired. These types of horizontal rotary conches provide a so-called"double-overthrow" action to thoroughly mix and bring new material intoits high shear zones in order to shorten the dry conching cycle time.Conches of this type, which are available from Richard Frisse GmbH keepthe scraping surfaces as large as possible to provide good shearingstress. Scrapers and kneader stirrer arms on the horizontal shaftsoverlap one another, providing powerful shearing in the masse and at thewalls.

During the course of the operation of traditional conching devices suchas these, the conching agitators rotate at a constant forward speed.During the course of such a traditional operation, the power imparted tothe intermediate product being conched will vary over time, particularlyas it begins to plasticize or when ingredients are added to the batchwhich have a primarily liquid consistency. This traditional approach caninclude two drive motors, one for forward operation at one constantspeed (dry conch), and the other for reverse operation at another(usually faster) constant speed (wet conch).

A possible alternative approach to improve conching would incorporate adrive arrangement that includes a primary drive motor and a second drivemotor. The primary one would impart a relatively slow speed to theconching members, while the secondary drive motor would impart a fasterspeed. Through suitable mechanical arrangements, this dual motorapproach would attempt to improve conching by having it take place attwo different speeds. In essence, by this approach, a higher power inputwould be imparted to the conching device when deemed appropriate. Thatis, for any interval of time, the product being conched would offer atotal resistance within the full load torque capability of the motor.One consequence would be to have higher input power intermittently"forced" into the product. However, imparting excessive energy toorapidly tends to form "grit" or hard, small particles that will remainwithin the finished chocolate, such typically being undesirable in mostapplications.

Another example of the delicacy of the balance which needs to bemaintained in order to provide consistent, superior chocolate productson a commercial scale is the difficulty in achieving the properviscosity of the finished chocolate in a time-efficient manner.Chocolate viscosity must be low enough in order to facilitate subsequentactivities such as enrobing or molding. In most applications, viscosityreduction requires the incorporation of an emulsifier such as lecithin.Traditionally the lecithin addition is carried out at the beginningand/or near the end of the conching operation.

In summary, the present invention is a process and apparatus or systemfor producing chocolate, with conching being a major step in the system.Chocolate refinings are subjected to conching conditions that aresubstantially determined by the varying consistency of the ingredientsthemselves while they are being conched. The present invention hasrecognized advantages will result from a feedback arrangement whereinthe consistency of the material being conched is itself "fed back" tocontrol the conching. By the use of a variable drive arrangement, theconching speed is automatically varied, depending largely upon theviscosity of the ingredients being conched, to such an extent that thepower imparted to the ingredients is maintained substantially constantvirtually throughout the conching procedure. In addition to varying theconching speed in order to maintain the conching power, the feedbackprovided by the interaction between the ingredients being conched andthe conching equipment can also be used to control ingredients, such asaddition of fat or emulsifier, and/or processing conditions used in theconching procedure, such as direction of blade rotation.

It is accordingly a general object of the present invention to providean improved process and apparatus or system for making chocolate.

Another object of the present invention is to provide an improvedprocess and system which accomplishes chocolate-making by utilizingfeedback of data from a conching operation in order to control theconching conditions and/or conching ingredients.

Another object of the present invention is to provide an improvedprocess and apparatus wherein conching is carried out in a manner tomaintain substantially constant power input to the equipment effectingthe conching procedure and to the chocolate refinings being conched.

Another object of this invention is to provide an improved process andapparatus or system to make chocolate while reducing processing timesand/or while optimizing the addition of costly ingredients such as cocoabutter.

Another object of the present invention is to provide an improvedprocedure and system for producing chocolate which maximizes theefficiency with which conching equipment is used while maintaining theproper consistency of the final chocolate product.

Another object of this invention to provide an improved process andapparatus which protects and respects the delicate, natural system ofchocolate.

Another object of the present invention is to provide an improvedchocolate-making process and system which substantially avoids gritformation while optimizing processing times.

Another object of the present invention is to provide an improvedprocess and system of producing chocolate which makes chocolate that isespecially consistent.

Another object of this invention is an improved process which isuniversal in its application to conching having the characteristic of anintrinsic rapid decline of the power imparted to the chocolate duringthe conching cycle.

These and other objects, features and advantages of the invention willbe clearly understood through a consideration of the following detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of the process and system accordingto the invention;

FIG. 2 is a detailed, perspective view of a portion of a typicalconching station;

FIG. 3 is a power curve and a speed curve for a typical prior artcommercial conching unit;

FIG. 4 illustrates a power curve and a speed curve which would resultwith a possible alternative conching unit which would embody a dualmotor approach not including the automatic adjusting and constant powerfeatures of the invention;

FIG. 5 is a power curve and speed curve for the conching unit of theprocess and system in accordance with the present invention;

FIG. 6 is a comparative plot of power curves depicted in FIGS. 3, 4 and5;

FIG. 7 illustrates patterns of data suitable for training to provide anautomatic prediction aspect of the invention;

FIG. 8 is a plot of viscosity (in centipoises) for various chocolatesamples when measured traditionally and when predicted automatically byan aspect of the invention; and

FIG. 9 is a plot of the deviation between the two viscosity valuesreported in FIG. 7.

DESCRIPTION OF THE PARTICULAR EMBODIMENTS

The process and system illustrated in FIG. 1 transforms the raw materialfor making chocolate into a finished chocolate product. Known rawmaterials enter a crumb maker 21 which forms a chocolate crumb in awell-known manner. The types of materials thus added would includechocolate liquor, sweetening agents such as sugar, milk components andwater, added at 22, 23, 24, 25. These may be incorporated to provideformulations in a manner that is generally well-known. Specific types ofcomponents and relative quantities thereof will be appreciated by thoseskilled in the chocolate making art. The precise quantities desired willbe delivered by any suitable mechanism or procedure. Chocolate crumb istransferred to a paste mixer 26 where it is mixed with a fat source,typically cocoa butter, at 27 to form a chocolate paste. The chocolatepaste is next refined in accordance with known techniques within arefiner 28. Thereafter, the chocolate refinings are delivered into aconching device 29.

Any number of conching devices are available commercially. Whateverequipment is used, it will include conching agitators to engage andphysically manipulate the raw materials being used to make thechocolate. Typical conching agitators are illustrated in FIG. 2.Included are a plurality of rotating shafts 30, 31. Mounted thereto areconching agitators such as the illustrated rotor arms 32 and blades 33.As can be seen in FIG. 2, these rotor arms and blades are oriented tointermesh with each other. In many conching devices, the type of actionimparted depends somewhat upon the direction of rotation. Detailsregarding the operation of these units is known from commercial conchingequipment available from various manufacturers.

Conching devices 29 which provide a basic construction that can bebeneficially incorporated into the present invention include those ofthe double overthrow type such as the DUC series manufactured by RichardFrisse GmbH. FIG. 2 is illustrative of this type of conching device 29.Center shaft 30 rotates in a clockwise direction and outer shafts 31rotate in a counterclockwise direction when the conch operates in itsforward mode. These directions are reversed when the conch operates inits reverse mode. The two outer shafts 31 and their associated rotorarms 32 and blades 33 present a smaller working diameter than does thecenter shaft 30 and its arms 32 and blades 33. They are within atemperature-controlling water-jacketed triple trough assembly.Conventionally, the forward mode is used during filling and duringso-called dry conching procedures wherein the chocolate being conched isin a firm, plasticized state. The zones between the central shaftassembly and the counter-current outboard shaft assemblies are areas ofintense shear. Upheaval or folding also occurs to more thoroughly mix byexposing more material to conching action.

Usually, the conching procedure includes the incorporation ofingredients in addition to the chocolate refinings. The most commonadditional ingredients are cocoa butter or other fat or fat substitutesources and emulsifiers such as lecithin or other emulsifier system.FIG. 1 illustrates sources 41, 42 for controlled delivery of these typesof additives. Heretofore, it was known to add emulsifier into theconching device 29 and to incorporate cocoa butter into the crumb. Afterconching was completed in these prior procedures, the chocolate wastransferred to a so-called standardizer wherein viscosity and usuallyother parameters such as particle size, fat content, moisture level andthe like are measured and needed adjustments are made. A commonadjustment made within a downstream standardizer is the addition ofcocoa butter to lower the viscosity of the chocolate. The presentinvention can eliminate the need for a downstream standardizer inasmuchas the standardizing can take place directly within the conching deviceby, for example, adjusting conching time and/or adding cocoa butterdirectly into the conching device and at the precise amount or amountsof cocoa butter or the like needed to effect the standardization. Thisachieves standardization with respect to function and equipment wherebyspace, assets and time are conserved.

Conching device 29 includes a motor 34 or other device for impartingrotary motion to the rotating shafts 30, 31. Transmission of the rotarymotion from the motor 34 to the rotating shafts 30, 31 is carried out byany suitable means. A suitable motor 34 is a squirrel cage inductionmotor rated at 110 kilowatts (Kw) and 60 hertz (Hz). In accordance withan important aspect of the present invention, a variable frequency driveis provided to allow the motor 34 to operate at variable speed outputsin order to drive the conching members 32, 33 at continuously varyingspeeds within a preselected range. A monitoring and controlling functionis accomplished. A suitable variable speed drive 35 is an AB1352Variable Frequency Drive available from Allen-Bradley Company, Inc. Itis fully digital, the frequency range of the inverter being from 0 Hz to200 Hz with a 0.01 Hz resolution. The drive can be programmed to includemany process control functions as an integral part of the drive. Thedrive 35 is rated at 290 kilovoltamperes (Kva).

The variable frequency drive 35 varies the speed of the motor 34depending upon the resistance to rotation of the motor which isencountered during its use. Same includes a known control circuit whichvaries the speed of rotation depending upon the resistance encountered.The invention does not merely program a fixed motor speed or a fixedsequence of motor speeds wherein the speed of rotation remains at acertain level until a predetermined time period has elapsed or until therotation direction has changed. Instead, by the present invention,continuous speed variability is imparted in response to the consistencyof the materials within the conching device 29, as opposed to anyspecific timing to modify the speed, if ever, between a selection ofspeed direction and/or motors running at different, constant speeds. Theresult of continuously varying motor speed in response to componentconsistency is a substantially uniform power applied to the materialsbeing conched. Roughly speaking, the power is held constant byincreasing the rotational speed of the conching device 29 when lessresistance is provided by the materials being conched and by reducingthe rotational speed when the resistance provided by the material beingconched is increased. FIGS. 3, 4 and 5, discussed herein, generallyillustrate these points.

With further reference to FIGS. 3, 4 and 5, these provide a plot ofpower data and of speed data. FIG. 3 shows these data for a prior arttraditional conching unit which operates essentially at a single forwardspeed and a single reverse speed. FIG. 4 is provided for illustrative,comparative purposes to show the power characteristics if one were toattempt to more efficiently impart power to a conching device by usingtwo substantially constant speed motors wherein the higher speed motoroperates in the nature of an overdrive unit in tandem with a larger,slower speed motor. FIG. 5 provides a power curve and a speed curve fora typical embodiment of the present invention.

The prior art power curve of FIG. 3 plots the power, in terms ofpercentage of the rating of the single speed forward motor and of thesingle speed reverse motor used, versus the time of operation of theconching device. The forward speed is slower than the reverse speed.During the first four hours of the conching procedure, the motor powersthe conching agitators to run in a forward direction at its constantforward speed. The power curve, which is depicted by the solid line,increases steeply during approximately the first hour of use (designated"fill" in FIG. 3) until the maximum power of the motor is reached. Atthis time, the conching chamber has been filled, and no further drymaterials are added. For approximately the next three hours (designated"dry conch"), the dry conching procedure takes place, with the motoroperating at the same speed throughout the dry conching period. It willbe noted that the power drops precipitously during the first one-halfhour or so of dry conching and continues to level off until only about20% of the motor's power rating is being imparted to the conchedmaterials. At about this time, additional cocoa butter and an emulsifierare added, and the motor is reversed to proceed with the so-called wetconching phase (designated "wet conch"). The increase in motor speed inthe reverse direction raises the power applied to the materials beingconched to about 30% of the motor rating. The power imparted again dropsoff, and the chocolate is discharged during the last fifteen minutes orso of the run (designated "dis."). The motor speed curve is illustratedin dotted lines. It will be noted a motor speed of about 800 rpm is theforward speed of the slower and more highly powered motor of this device(designated "slow forward"). The change in motor speed to about 1600 rpmis indicated by the rise in the speed curve when in reverse (designated"fast rev."). The actual energy imparted to the materials being conchedis indicated, of course, by the area under the power curve.

The comparative arrangement shown in FIG. 4 illustrates the effectswhich would be brought about by a dual motor arrangement wherein afaster constant speed motor would be used as an overdrive for a slowerconstant speed motor. The illustration shows the faster speed motor toimpart its same constant speed when reversed. This does not embody thepresent invention and is presented as a comparative alternative to theprior art arrangement shown in FIG. 3. The filling operation (designated"fill" in FIG. 4) corresponds to a dry phase wherein the chocolate crumbmaterial is added during about the first hour of conch unit operation(designated "dry phase"). As illustrated by the dotted speed curve, inthe initial phase, the faster speed motor rotates the agitatorsforwardly (designated "fast speed fwd."). During this inflow or dryphase operation, the faster speed overdrive ceases, and the slowerspeed, higher capacity motor provides the driving force (designated"slow speed fwd."). The slower speed motor is illustrated as operatingat about 800 rpm, and the faster motor is shown as operating at about1600 rpm. Both motors can have a rating on the order of about 132kilowatts. At the time of this switch to the slower speed motor, therewould be a precipitous drop in the speed curve, as well as in the powercurve. Thereafter, the power curve would rise steeply until the flow ofchocolate crumb material into the conching unit ceases. At this point,conching would begin (designated "dry conch" and "tough plastic phase"in FIG. 4). Initially, there would be a sharp drop in the power curve,which drop would continue until the power is "spiked" by again engagingthe faster speed motor, after which a relatively steep drop again wouldoccur. Subsequently, the faster speed motor would be reversed indirection (designated "fast speed/rev.") which again would result in aspiking of the power due primarily to a change in the action imparted bythe agitators when run in the reverse direction as opposed to theforward direction. Shortly thereafter, the effect of this reversal"spike" would wane. This rotation speed would continue until the toughplastic phase of the dry conching operation develops into a liquid phase(designated "liquid"). At first a wet conching operation, would occur(designated "wet c."), after which the chocolate would be discharged(designated "dis.").

Results achieved in accordance with the present invention areillustrated in FIG. 5. Conching is carried out automatically based uponthe consistency of the product being conched. The invention can becharacterized by four different phases based upon the consistency of theproduct: a dry phase, a tough plastic phase, a soft plastic phase, and aliquid phase. Preferably, as illustrated, the chocolate refiningscontinue to be filled (designated "fill") throughout the initial dryphase (designated "dry phase/fwd." in FIG. 5) and during the beginningstages of the tough plastic phase (designated "tough plasticphase/fwd."). Dry conching (designated "dry conch") continues through toconclusion of the tough plastic phase and during the soft plastic phase(designated "soft plastic phase/rev."). The liquid phase (designated"liquid phase/rev.") begins with an almost instantaneous drop in powerwhen the emulsifier is added, and wet conching proceeds (designated "wetc."). Shortly thereafter, the liquid chocolate is ready for distributionout of the conching unit (designated "dis."). It will be noted that thepower is maintained substantially constant throughout the dry conchingoperation, the power being at the rating of the variable speed drive 35.

An assessment of the dotted-line speed curve indicates how thissubstantially constant and maximum power output of the motor is able tobe maintained. The maximum speed of this motor of about 2100 rpm isinitially set in this illustrative example and then drops in response toplasticization. The power imparted to the chocolate refinings continuesto increase until the chocolate refinings being filled begin to beplasticized by the relatively fast movement of the agitators. This powerincrease continues until the desired maximum power is reached, and thetough plastic phase begins. Even during filling, the motor speed dropsin response to increased resistance imparted to the conching agitatorsby the freshly added chocolate refinings, and a plastic condition isevident even during filling. Once conching begins, this resistancebegins to subside even further, and the variable speed drive senses thisreduction in resistance and automatically increases the motor speedwhile the motor continues to operate in the forward direction.

When a target viscosity or other suitable parameter is reached,preferably the variable speed motor unit is automatically instructed toreverse its direction. This occurs when the chocolate refinings havebeen sufficiently plasticized so the soft plastic phase can beinitiated. The present invention recognizes that reversing directionrelatively early in the dry conching procedure improves conchingefficiency. FIG. 5 shows a small initial slow-down in motor speed inorder to maintain the constant power rating. More particularly, when theagitators of many commercial conching devices are run forwardly,shearing and kneading occur as the chocolate refinings are moved by andbetween the agitator paddles. When the agitators are run in reverse,chocolate refinings are forced between back edges of the agitatorpaddles and the wall of the conching enclosure to generally extrude theproduct being conched.

The resistance encountered during rotation is translated by known meansto the variable speed drive into a frequency signal which corresponds tothe viscosity of the chocolate within the conching device 29 during anystage of the operation of the invention. If, at any stage, the viscosityor other parameters such as fat content reach a value at whichemulsifier or fat should be added to have the final chocolate exhibit atarget parameter, the central processing unit 36 signals the source 41,42 to deliver the proper amount of additive(s) into the conching unit29. If the feedback response provided by the chocolate being conchedindicates the viscosity and/or other monitored parameters are within thetarget values for the particular chocolate being prepared, there may beno need to incorporate additional components such as costly cocoa butterand/or there may be no need to continue the conching until thecompletion of a conventionally designated duration. This feedbackprocedure, which can be carried out with the aid of a so-called neuralnetwork, in effect accomplishes chocolate standardizing directly in theconching unit, thereby eliminating the need for a standardizationstation downstream of the conching unit.

FIG. 6 provides an illustration of the advantageous aspect of thepresent invention wherein substantially increased energy is imparted tothe chocolate refinings when compared with other possible approaches.The respective power curves of FIGS. 3, 4 and 5 are superimposed on oneanother, the respective curves having been time coordinated to permit agenerally direct overlay of these power curves. The increase imparted bythe FIG. 5 power curve when compared with the prior art FIG. 3 powercurve is illustrated by the sum of the cross-hatched area and of thesolid area of FIG. 6. The total of this difference approaches 50kilowatt hours of energy per ton of product. More specifically, theenergy imparted is approximately 30 kilowatt hours per ton whenprocessed in accordance with the power curve illustrated in FIG. 3,while the imparted energy is about 80 kilowatt hours per ton of productby the power curve in accordance with the invention which is illustratedin FIG. 5. The cross-hatched area of FIG. 6 generally illustrates thepower advantage of the present invention over the comparativeillustration of FIG. 4.

The power values and speed values illustrated in FIGS. 3, 4, 5 and 6 arereported in terms of the motor output. It will be appreciated that likevalues for the conch agitators are lower. The extent that these valuesare lower is substantially the same for the respective curves so long asthe design and size of the conching agitators and vessels associatedwith the respective motors are substantially the same.

With more particular reference to the motor 34 and the variable speeddrive 35, it is important that the variable speed drive have about twoor three times the power rating or size of the power rating or size ofthe motor itself. For example, the motor discussed herein is rated at110 kilowatts, while the drive has a rating of 290 kilovoltamperes, afactor of about 2.6. This relationship is found to be particularlyhelpful during the startup phases for a conching unit under full load. Alow frequency startup is also desirable. For example, the variable speedunit should permit motor startup at a very low frequency, for examplebetween 1 and 2 hertz in order to avoid the delivery of excess currentto the motor during startup and a resultant tripping of the motor'scircuit breaker.

As previously stated, a feedback procedure can be incorporated, and itcan be facilitated by a neural network 37. A typical network in thisregard utilizes a group of processing elements grouped together inlayers or slabs. Each layer of processing elements is interconnectedwith the elements from other layers, the interconnections being calledweights. The network is trained as it learns to recognize and adapt toits situation. A properly trained network finds patterns in voluminousdata input to it. Suitable software packages useful in connection withthis aspect of the invention include Neuralworks Professional II⁺available from NeuralWare, with a typical architecture being theBackpropagation network. The input data are collected digitally using ananalog-to-digital converter. The inputs include the power supplied todrive the motor and the frequency of the variable speed drive. Outputsinclude fat content, viscosity and chocolate load or weight.

A training iteration is used in accordance with generally knownprinciples wherein numerous inputs are presented to the network such asthose illustrated in FIG. 7. FIG. 7 is the pattern for a particularchocolate batch in a particular conching device. It represents a load of6620 Kg having a particle size of 19 microns, a water content of 0.93percent, a fat content of 29.07 percent, and a viscosity of 24,500centipoises. Inputs such as that shown in FIG. 7 in effect train thenetwork to recognize patterns, often in terms of instantaneous slopes ofthe data curves. The trained neural network is then available to predictthe parameters of each run within the conching device 29. The networkpredicts results in order to validate or check the load or weight of thechocolate being conched, in order to establish the fat content of thechocolate being conched and in order to predict the final viscosity ofthe conched chocolate product.

Using this arrangement, the viscosity predicted by the neural networkfor a number of samples was compared with viscosity measurements takenby a traditional quantative measurement procedure for each of thesamples, which traditional procedure has a margin of error of about ±6%.FIG. 8 illustrates the good correlation between the measured viscosityand the viscosity predicted by the neural network. FIG. 9 plots of thepercentage "error" between the two viscosity values. It will be noted,with one exception, each "error" is less than the margin of error of thetraditional viscosity measurement procedure.

Interaction among the motor 34, the variable speed drive 35, the centralprocessing unit 36, the neural network 37 and the additive sources 41,42 preferably proceeds as follows. By way of a continuous interaction,the variable speed drive inquires of the motor and provides the commandsfor its operation in terms of frequency. The relationship between thevariable speed drive and central processing unit is also two-way whereinthe central processing unit inquires of the variable speed drive toobtain frequency data and also provides the commands for modifying itsoperation such as by dictating when the drive shaft should ceaseoperation of the motor and when the motor operation is to be reversedsuch as upon reaching a threshold frequency value. The neural networkinquires of the variable speed drive for the pattern of data beinggenerated by the chocolate being conched. The neural network then passesinformation to the central processing unit to present commands to otherequipment, particularly the variable speed drive and the additivesources. More specifically, after the neural network carries out itspattern recognition task, it provides input to the central processingunit. Armed with this input, the central processing unit instructs anadditive source, for example, when to add emulsifier and/or how much toadd, and/or instructs the variable speed drive as to the length ofconching time needed for the particular chocolate being conched. Theresult is an especially efficient conching procedure which conches foronly that length of time needed to achieve the target viscosity for thatparticular chocolate and adds only the amount of fat needed to achieve atarget fat percentage.

Consistency is enhanced. The conched chocolate can have a moreconsistent viscosity from batch to batch, without requiring anypost-conching standardization. Conching times in total are reducedbecause unnecessary conching is eliminated. It is thus possible to conchmore product during the same hours of operation of a given conchingdevice. Each conching device is increased in its conching capacitybecause of the more efficient operation according to the invention. Forexample, it is possible to effectively conch 7000 Kg of chocolaterefinings within a conching device having a capacity of 6000 Kg, whichis a capacity increase of about 16 percent.

It will be understood that the embodiments of the present inventionwhich have been described are merely illustrative of an application ofthe principles of the present invention. Numerous modifications may bemade by those skilled in the art without departing from the true spiritand scope of the invention.

I claim:
 1. A flowable conched chocolate having an optimized fat contentand a preselected maximum viscosity of the conched chocolate which islow enough for enrobing the chocolate, the conched chocolate comprisingchocolate refinings and a fat source which had been mixed together andsubjected to conching conditions in order to form and to lower theviscosity of a finished flowable conched chocolate, said flowableconched chocolate having no additional fat source in excess of an amountneeded to impart said preselected maximum viscosity to said flowableconched chocolate, said amount of the fat source being about 29 weightpercent, based on the weight of the conched chocolate.
 2. The conchedchocolate in accordance with claim 1, wherein said flowable conchedchocolate had not been subjected to post-conching standardization andwherein said amount of fat source is lower than otherwise substantiallyidentical flowable conched chocolate which had been subjected topost-conching standardization that includes addition of fat source. 3.The conched chocolate in accordance with claim 1, wherein said flowableconched chocolate has a reduced fat content at said preselected maximumviscosity.
 4. The reduced-fat conched chocolate in accordance with claim1, wherein said fat source is cocoa butter.
 5. The reduced-fat conchedchocolate in accordance with claim 1, wherein said fat content is from afat source including cocoa butter.
 6. The conched chocolate inaccordance with claim 1, wherein said amount of fat source of theflowable conched chocolate is at least one weight percent less than aflowable conched chocolate which required the addition of fat in orderto achieve said preselected maximum viscosity.
 7. The conched chocolatein accordance with claim 1, wherein said amount of fat source of theflowable conched chocolate product is less than the amount of fat of aflowable conched chocolate which required the addition of fat in orderto achieve said preselected maximum viscosity.